The billboards warning of prison time and massive fines for voter fraud listed their sponsors only as “an anonymous family foundation.”

Now the group One Wisconsin Now claims the Einhorn Family Foundation anonymously bought the billboards in low-income and minority neighborhoods in Cleveland and Columbus, as it did in Milwaukee in 2010.

The billboards came down last week. And one of their biggest critics, Congresswoman Marcia Fudge, thinks that – and the revelation of the sponsor – is enough.

"Even though in my mind, it is not free speech. It is incendiary and it is racist. But I would suggest that they would probably argue that it was free speech. We are angry at how people think that we are so gullible that any little thing like a billboard is going to say to us, 'You know, I don't think I'm going to go out and vote. It's going to be too difficult.' It has had the reverse effect. Now they're saying, 'Because you want to stop me from doing it, I am more determined to do it than ever before'."

The Einhorn foundation, the family and a key funder of the foundation did not return calls for comment.

After the billboards went up and protests broke out, ClearChannel Outdoor agreed to remove them, saying they violated its policy against anonymous political messages.